Impeller for dishwashing machines



Nov. 14, 1950 H. G. DAVIS IMPEILER FOR DISHWASHING MACHINES Filed July 3, 1944 Y f3 Jf INVENToR.

ay/WM( 17mm/fr Patented Nov. 14, 1950 UN [TEDu STAT ES` :PA'I: EN OFFILC IE.

IMPELLERfFORfDSHWASHING MACHINES.-

Harold 'G'. Davis, Denver, Color Application July-3,1944, Serial No. 543,392

cal and this stream `will be continuously rotated about the Vertical axis so asto strike the dishes atan innite number of diiierent angles so as to efliciently.. cleanse the same.

Other objects are to provide highly efcient means for gyrating the impeller about its vertical axis which will operate regardless of the depth of water in the tank'; to provide an efcient oiling device for the impeller which will prevent the oil from vbeing forced from the bearings under the influence of heat; to provide highlyveicient bearing sealing means which will preventthe entry of water into the bearings;

and to provide an elective brake construction. by means of which the speed of gyration can beY pre-set at anyv desired speed.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and eiciency. These will become more apparent from the followingjdescription.

In the following detailed description of "the invention, reference is had tothe accompany-` ing drawing which forms a-part-hereof. LikeA numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a plan view of the improved impeller.

Fig. 2 is a vertical section therethrough taken on the line 2-2, Fig. 1. In this view the impeller blades have not been cut by the section for ,the purpose of clarity of illustration.

Fig.t 3 is a detail cross-section-taken on the line 3-3,'Fig. 2.

Figul is a similar cross-section Vtaken -on the line 4 4, Fig. 2.

In the drawing, the related parts of the dishwasher have been omitted since this application pertains only to the impeller portion thereof. However, the position of the bottom of a dishwashing tank is indicated at I9 and the position of the top of a fan housing is indicated at II.

The entire structure is supported in a cylindricalv-outer housing I2 having a top peripheral. flange I3. The rriange rests upon a suitable sealing gasket .I4 whichy sealsit to thefbottom I0 of the tank. A similar.` sealing gasket I5 .is placed. between .the two members I0 and II and the entire. structure is. clamped. to. the members,v I0- and lI I .by means of a .clamp nut It. The bottom- Illof the` outer housing is ,closed bya threaded bottom .cap ..I l. v

An inner housing I8V is rotatably mountedV within the outer housing. I2 and extends above the top thereof. The upper extremity of the inner housing. terminates in abearing cup I9, the. axisof whichis at an acuteangleto the axis ofthe inner housing I8.l This angle may be any suitable degree, it having been foundthat an angle of '17 is vthe mostsatis'factory. The cup..l9"is. enclosedby means ofja top cap 20 threadedthereon.A

A-. hollow, cup-.like bearing member 2I is threaded on the lower extremity` of-the inner housing I8 and is rotatably mounted within the outer housing I2 `so as to rotatably support-the latter and. maintainit accuratelyA on its axis. Theinterior of 'the hollow bearing member 2l is. sealedlfrom theinterior of the tank'by` means. of an. inverted sealing cup, 22 which is constantly urged. against the `top of the outer housing` I2. by. means of` a, compression spring 23: which rests' on the bottom of the bearing member 2|.

It .can be seen that the above construction allows the inner housing to rotate freely about its axis, the rotation being snubbed by the friction between the cup 22 'and the top of the housing I2. This snubbing action can be pre-setby choosing the springu23k of the proper strength.

Atrunnion bearing' 24 is rotatably mounted in the cup IS'and carries a hollow, axially-'extending spindle 25which extends through and above the cap` 20; The bearing 24 is sealed from the interior of the tank by means'of an inverted sealing cup2ga` and sealing spring 2l,` similarly to the previouslydescribed sealing,L means. kThe cup26 isjconstantlypurged.against the capj2b`y means 4of the *actionV of the springv 21.'

A hollow impeller'hub 28"is vwedged onv vthe spindle 25, the `latterjbeing taperedto receiveit. The "skirt" of the Ahub 28-extends downwardly about cup I9. Two oppoSitely-projecting, tangentially-mounted, curved impeller blades 29 project oppositely outward from the skirt of the hub 28. These blades are so curved as to impart a scooping action on the water to throw it upwardly about the axis of the spindle 25 in a more or less conned spiral stream.

The hub 28 is held in place on the spindle 25 by means of an oil cup 3U threaded onto the upper extremity of the latter. The interior of the cup is open to the hollow interior of the spindle 25. The cup is closed by means of a threaded cup cap 3| provided with a suitable sealing gasket, 32 which forms an air tight seal onthe cup 30. It has been found in prior impeller mountings that when the latter become heated through the action of the hot water and the friction of rotation, the oil therein will be expanded and forced through the bearings into the tank. In the improved construction, any expansion in the oil is absorbed in compressing the entrapped air in the top of the oil cup 30 so that the oil will not be forced from the bearings.

The impeller is driven through the medium of a drive shaft 33, the lower extremity of which projects below the bottom cap I1. The lower extremity is suitably threaded, as shown at 34, to provide a connection for any suitable driving element. A sealing skirt 35 is formed on and surrounds the shaft 33 immediately above the cap I1. This skirt contains a sealing cup 36 against which a Spring 31 acts to seal the housing above the shaft 33. The spring 31 acts to constantly urge the cup 36 against the cap I1 to prevent water or other liquid from entering the outer housing I2.

A section of flexible shafting 38 is iixedly secured in the shaft 33 in any desired manner, such as by soldering it in a receiving socket therein. The upper extremity of the shaft 33 contains a conical concavity in which the flexible shaft 38 may move. The upper extremity of this shaft 38 terminates in a terminal member 39 which rests in the hollow spindle 35. The terminal member is notched and a key member 40 in the spindle extends across this notch to provideA a driving connection for the impeller which will allow freedom for axial movement of the terminal member 39.

The bearing member 2| and the inner housing I8 are supported on a combination thrust and bearing member 4I which is rotatable within the outer housing I2. The thrust member 4I has the proper thickness to support the inner housing I8 at the desired height when the cap I1 has been screwed in place to its final position. It is this bearing member 4I which supports the entire rotating assembly at the proper height in the tank.

The inner housing I8 is rotated through the medium of a scoop 42 which is supported immediately over the lowermost portion of the blades 29 upon a scoop arm 43. VThe scoop arm is formed on and extends from a vane plate 44 which is attached to a suitable projection on the inner housing I8 by means of suitable attachment screws 45 or in any other desired manner.

The rotation of the blades 29 creates a whirling action in the water about the impeller. This whirling is interrupted by the vane plate 44 to break the latter into lateral currents for assisting in the washing of the dishes. This action also imparts a rotative movement to the vane plate 44 which causes it to tend to rotate the inner housing and to gyrate the axis of the impeller. It has been found, however, that this action alone is not sufficient to give the desired gyration speed to the impeller. Therefore the rotation is assisted by the scoop 42 which is placed directly over the discharge of the blades 29. The scoop is curved so as to produce a rotative reaction on the arm 43 due to the current of water leaving the blades. This rotative reaction is transmitted through the arm 43 to assist the vane plate 44 in gyrating the impeller.

It will be noted that the arm 43 is arched as shown at 46 to allow it to pass the projecting impeller mechanism and that the scoop is over the lowest position of the blades so that it will receive water even though the water level in the tank be below the middle of the impeller.

While a specic form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. In a dishwashing machine of the type having an impeller shaft axially positioned within a rotatable housing which in turn is positioned within a stationary outer housing, means for resisting rotation of said rotatable housing comprising: an annular bearing member secured upon said rotatable housing and projecting outwardly toward said outer housing; a cylindrical compression spring surrounding said rotatable housing and resting against said bearing member; and an annular sealing member surrounding said rotatable housing and being positioned between the other extremity of said spring and said outer housing, said spring acting to force said sealing member into frictional engagement with said outer housing to resist the tendency of said rotatable housing to rotate with said impeller shaft.

2. In a dishwashing machine of the type having an impeller shaft axially positioned within a rotatable housing which in turn is positioned within a stationary outer housing, means for resisting rotation of said rotatable housing comprising: a hollow, cup-like bearing member secured upon the lower extremity of the rotatable housing, said bearing member rotatably supporting the rotatable housing within the outer housing; an inverted sealing cup surrounding said rotatable housing above said bearing member; and a spring positioned in said bearing member and acting to force said sealing cup into frictional engagement with said outer housing to resist rotation of said inner housing therein.

HAROLD G. DAVIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,666,013 Jackson Apr. 10, 1928 1,934,970 Davis Nov. 14, 1933 2,041,177 Davis July 14, 1936 

